Hello and Welcome to the Idiot's Guide to Conjuring Spirits! Right now it's 12:38 A.M. Central Time and I'm stone-cold out of my mind. So, while I'm in a state of mental haze, why don't I clear up my thoughts by writing a guide of what I do best?
This set of rules is more like a guideline to the behavior of spirits and how they will react to situations. And how you should react to keep them from kicking your ass. They are simle enough that a child could understand them, but meaningful enough so that the oldbies can work with them (and, if you were good at it, you can notice the trends that I noticed aswell and pat yourself on the back for doing a cool job).

Call only what you can handle.
-For as the river will flow into the cup, the Spirit's wrath will flow down and crush whoever dares to call them. More experienced practitioners should be able to call upon spirits of raw violence and hate, but to expect someone who just flipped to page 45 in a Amazon grimore and expect to summon an Oni, Demon, or Dragon is just sad. The consiquences could be dire.
Not all Spirits act agressively, yet not all Spirits will be kind and gentle. But all Spirits will ignore you and go back home, or just beat you down when you try to force them from their "home" into your circle

Respect the Spirits.
-The Spirits are embodyments of the wonderful and the devient in this world, and as such they should be treated with respect. Not all Spirits are vile, viscious creatures. But likewise it should be realized that all things should be treated with respect. Even if it was a Spirit to be vanquished, captured, or whatever you did to it, respect it in all manners.

Never EVER break the Circle.
-No matter what a Spirit tries to get you to do, never reach into the circle that binds them there. If you're lucky, they'd just laugh and vanish. If you're not, they'll throw you down and teach you some manners before going off. If you break the circle, you are at the Spirit's mercy.

Avoid engaging in Pacts.
-Although this is more like a guideline rule, it still stands. The best Pact is the Pact you never have to honor. If a Spirit tries to entice you into a Pact, remember that the Spirit's relying on you to be able to be dismissed and go on with their lives. Use that as kind leveredge if you want to avoid a pact, or simply say no.

Avoid games of chance or skill.
-It would be wiser still to avoid gambling or gaming with Spirits, although I've found that a good game of tag with a Fae to be quite enjoyable. Make sure what they ask is of no consiquence, and if it's for favors be sure that it's layed out exactly what it is for. The Spirit will usually be good at the game it challanges you to, and you better use all your stuff if you plan on beating a pro that's been around for possibly hundreds or thousands of years.

Make your Demands simple.
-Unless you've gotten a mischiefous Spirit, then you don't have to worry about long and complex commands. Spirits would most likely be back at doing what they love rather than spend their precious time with you and worrying about your needs. After introductions, state the demand polietly for you being able to dismiss them, and honor that statement.

Never change your demands.
-Although there are some emergencies that may call for it, it's wise not to anger Spirits with your little side-quests. Ensure that you hold to your word, and free them when they've completed their task. Be sure to thank them, and politely release them of their bonds to this place. I'm sure you yanked them out in the middle of a conversation with friends, family, or even while they were busy doing other things, and they'd like to get back to it.

Well guys, that's all I have. I might add onto it, but for now I'm tired... Time to get on my metaphorical broomstick and fly away~

"Water, water, everywhere,
And all the boards did shrink;
Water, water, everywhere,
Nor any drop to drink."